Chromatography Forum

Dear all,
i am newcomer of LC-MS/MS i am working on liphophilic NCE and developing method, i am facing the problem of carryover ie.more than 50% of LLOQ So how to avoid the carryover what type of solvent we have to prefer if i have tried IPA:Acetone:Methanol(8:1:1) and methanol..

Sadanand Mallurwar,

Research Associate

Drug Metabolism and Pharmacokinetics,
Lupin Research Park,

Pune.

carry over problem may be due to improper rinsing of syringe needle, so try to
change the rinsing solution to that in which your drug is having good solubility increase the rinsing volume
Decrease the contact area of needle with analyte i.e. increase needle height..

Before you do anything you have to establish where/how the carry-over is produced. If its elimination is not obvious you can report back here.